In September, Aachen typically sees daytime highs of 18.8°C and overnight lows around 9.6°C. Compared to the annual average high of 13.2°C, September runs +5.6°C.
September in Aachen averages a daytime high of 18.8°C and an overnight low of 9.6°C.
September runs +5.6°C compared to Aachen's annual average high of 13.2°C, ranking #4 of 12 months by warmth.
Plan for daytime highs near 18.8°C and cooler evenings around 9.6°C.